Retractable dummy bar guide

ABSTRACT

A chute is provided below the exit end of a continuous casting mold to guide the dummy bar into the mold. Moving means are provided to move the chute away from the mold assembly after casting starts so that the chute will not be damaged by breakouts.

United States Patent Precht et al.

[ 1 Apr. 25, 1972 RETRACTABLE DUMMY BAR GUIDE Horst Precht, Jamaica,N.Y.; Herbert Fastert, Wyckotf, NJ.

Concast Incorporated, New York, NY.

Apr. 14, 1970 Related [1.8. Application Data Continuation of Ser. No.662,420, Aug. 22, 1967, abandoned.

Inventors:

Assignee:

Filed:

App]. No.:

US. Cl.....

Int. Cl

Field of Search References Cited UNlTED STATES PATENTS 8/1967 Foldessy..l64/l74 3,446,270 5/1969 Michelson 3 ,448,789 6/1969 Gallucci3,495,651 2/1970 Rokop et al ..l64/282 X FOREIGN PATENTS OR APPLICATIONS1,280,393 ll/1961 France ..l64/82 Primary Examiner-R. Spencer AnnearA!t0rney-Sandoe, Hopgood & Calimafde [57] ABSTRACT A chute is providedbelow the exit end ofa continuous casting mold to guide the dummy barinto the mold. Moving means are provided to move the chute away from themold assembly after casting starts so that the chute will not be damagedby breakouts.

3 Claims, 2 Drawing Figures This is a continuation of U.S. Pat.application No. 662,420 filed Aug. 22, 1967, now abandoned.

This invention relates to the art of continuous casting and, moreparticularly, relates to an improved apparatus for guidance of the dummybar into the continuous-casting mold.

In continuous casting plants the molten metal is poured into anopen-ended water-cooled mold which chills the metal in contact with themold walls to form a peripheral skin defining the billet or strand. Toinitiate the casting operation it is necessary temporarily to seal thebottom of the mold in order to contain the molten metal within the mold.This has been done by insertion of a dummy bar into the exit end of themold. After the mold is filled with molten metal to the desired levelthe dummy bar is extracted, pulling from the mold the cast strand. Thelevel of the molten metal in the mold is maintained by pouring moltenmetal into the mold at the same rate as the metal is solidified andextracted from the mold. The strand issuing from the mold encases amolten core within the defining peripheral walls. This strand is passedthrough water sprays for further cooling of the strand.

In the continuous casting plants known to the art a plurality of rollersare provided just below the continuous casting mold. These rollers havethe function of guiding the dummy bar as it is pushed upwardly to sealthe exit end of the mold and also provide guidance for the issuingstrand. It has been found that the issuing strand can be successfullywithdrawn without roller guidance, although in some cases a single pairof rollers located immediately below the mold, as shown in the drawing,may be useful to support the issuing strand and to center it withrespect to the mold. In fact, the usual series of rollers may interferewith the flow from some types of water sprays. However, elimination ofthese rollers has been impossible in curved mold machines due to therequired guidance of the dummy bar. Since continuous casting plants mustbe designed to encounter breakout, the presence of the roller guidesbelow the mold has been of particular disadvantage since they may bedamaged by hot metal during a breakout.

It is therefore an object of the present invention to provide animproved apparatus for dummy bar guidance.

In accordance with this object, there is provided in a preferredembodiment of this invention a chute positioned below the exit end ofthe mold to guide the dummy bar as it is inserted into the exit end ofthe continuous casting mold. Means are provided to move the chute aftercasting starts. The chute is moved sufficiently far away from the moldassembly so that it cannot be damaged by hot metal in the event of abreakout. The movement of the chute exposes the issuing strand to thefull intensity of water spray nozzles positioned below the mold.

Having briefly described this invention it will be described in greaterdetail in the following portions of this specification which may best beunderstood by reference to the accompanying drawing of which:

FIG. 1 is a partially sectioned elevation view in accordance with oneembodiment of the present invention, and

FIG. 2 is a partially sectioned elevation view of another embodiment ofthe present invention.

In FIG. 1 there is shown a continuous casting mold having an open-endedmold cavity 12 extending therethrough. The mold cavity, defined by thewater-cooled walls of the mold, is curved. As is conventional the moldis oscillated on a curved path to cast a curved strand. Below the exitend of the mold there is provided a chute 14 having a curved chute face16 to match the curvature of the strand receiving guidance arrangementpositioned below the chute in conventional manner. The chute is mountedon pin 18 which serves as a pivot. A hydraulic ram 20, having anactuating rod 22 coupled to the chute by the pin and bushing coupling 24is provided to move the chute from the operating position shown to asecond position illustrated in dotted outline.

In operation the chute is positioned in the operative position to guidethe dummy1 bar 26 as it is moved u wardly into sealing engagement witthe exit end of the mol After the filling of the mold with molten metaland initiation of casting by withdrawal of the dummy bar with the strandaffixed thereto, the chute is moved to the inoperative position byactuation of hydraulic cylinder 20. The movement of the chute to theretracted position ensures that the chute will not be damaged by abreakout. The strand travels the short distance (approximately 4 to 6feet) unsupported where the strand now receives the full application ofthe water spray from the spray nozzles positioned along the strand pathin conventional manner.

In FIG. 2, there is shown a curved mold 10 with a chute 28 positionedbelow the mold. The chute is provided with a frame member 30 having aslot 32 therein. A stationary pin 34, which may be mounted on a portionof the frame (not shown) of the casting apparatus, engages the slot 32.The chute is also provided with a rearwardly extending frame member 36having a slot 37 slidably receiving another stationary pin 38, whichalso may be mounted on the frame of the casting apparatus. The pins 34and 38 thus support and guide the chute 28 for generally horizontalmovement. The frame member 36 is coupled to the actuating rod 40 of ahydraulic or a pneumatic ram 42. Operation of the ram 42 moves the chutefrom the operative position shown in solid outline to a retractedposition shown in dotted outline as indicated by arrow 44.

Thus, in both embodiments, the roller apron immediately below the moldcan be eliminated.

This invention may be variously modified and embodied within the scopeof the subjoined claims.

What is claimed is:

I. In a continuous casting plant having a continuous casting mold forcasting a curved strand, the improvement comprising a chute having anopen chute face curved to match the path of the lower surface of thecast strand and adapted to guide the end of a dummy bar into the exitend of the mold, said chute having an operable position immediatelybelow said casting mold and in the path of the lower surface of the caststrand, and means for moving said chute from said operable position toan inoperative position retracted from the path of the lower surface ofthe issuing strand.

2. The improvement in accordance with claim 1 in which said chute ispivoted at one end thereof, and in which said retraction means comprisesa ram having an actuating rod coupled to said chute at a positionseparated from said pivoted end, said ram being operable to move saidchute from the operative position to the retracted position.

3. The improvement in accordance with claim 1 in which said chuteincludes a frame member extending forwardly therefrom, said frame memberbeing provided with a slot, said chute being provided with a rearwardlyextending frame member, a second slot in said rearwardly extending framemember, and pins engaging said slots for guiding the movement of saidchute to a first position in which said chute face guides a dummy barinto the exit end of the mold and then to a second position away fromthe path of a cast strand from the mold, and in which said moving meanscomprise a ram having an actuating rod, said actuating rod being coupledto said rearwardly extending frame member.

1. In a continuous casting plant having a continuous casting mold forcasting a curved strand, the improvement comprising a chute having anopen chute face curved to match the path of the lower surface of thecast strand and adapted to guide the end of a dummy bar into the exitend of the mold, said chute having an operable position immediatelybelow said casting mold and in the path of the lower surface of the caststrand, and means for moving said chute from said operable position toan inoperative position retracted from the path of the lower surface ofthe issuing strand.
 2. The improvement in accordance with claim 1 inwhich said chute is pivoted at one end thereof, and in which saidretraction means comprises a ram having an actuating rod coupled to saidchute at a position separated from said pivoted end, said ram beingoperable to move said chute from the operative position to the retractedposition.
 3. The improvement in accordance with claim 1 in which saidchute includes a frame member extending forwardly therefrom, said framemember being provided with a slot, said chute being provided with arearwardly extending frame member, a second slot in said rearwardlyextending frame member, and pins engaging said slots for guiding themovement of sAid chute to a first position in which said chute faceguides a dummy bar into the exit end of the mold and then to a secondposition away from the path of a cast strand from the mold, and in whichsaid moving means comprise a ram having an actuating rod, said actuatingrod being coupled to said rearwardly extending frame member.